/**
 * Add a class extend method to funcitons
 * @version 1.0
 * @param {Funciton} argument[0] Superclass to extend
 */
if (!Function.prototype.extend) {
	Function.prototype.extend = function () {
		var F = function () {};
		F.prototype = arguments[0].prototype;
		this.prototype = new F();
		this.prototype.constructor = this;
	};
}